Pretty much. Anti semitism had pretty much died down by the time I was a kid, but many of the older folks, like my first grade teacher, may have been influenced by it. Basically,"Jews are left handed and that's bad". Today, it would be the Muslims in underdeveloped areas that use their left hand to wipe without benefit of toilet paper that sounds the alarm. The unclean hand.
I didn't notice any other lefties in the class, although it comprised of about 30% Jewish kids. Go figure.
Anyway, back in the day, being a leftie was considered an evil omen partly because of what I mentioned. Being forced to favor one hand over the other does cause some problems or benefits. With me, I can use either side of my brain. One reason why I did well in math and language. Most people are proficient in one or the other. Go figure.